Closure for exhaust pipes



Feb. 12, 1952 c. H. HARMON ErAL CLOSURE 'FOR EXHAUST PIPES Filed Nov. 20, 1948 di H. JNVENToRs z/ze aff mi vm y far/71071.

d 5y /J Patented Feb. l2, Y1952 UNITED@- sTATEs PATENT OFFICE 'V CLOSURE FOR EXHAUST PIIAES Cline Harry Harmon and Dorathea L. Fort, Waterloo, Iowa, assi gnors to Waterloo Foundry Company, Waterloo, Iowa,1a copartnership Application November 20, 1948, Serial No. 61,148

y v,2 Claims. 1 Y

The present invention `relates to a closure device for protecting the open end of an upright terminal portion of an exhaust pipe of gasoline and diesel engines and the like. Devices of this general type serve to exclude rain, snow, dust, dirt and foreign matter from entering .the exhaust pipe when the engine is not operating, and automatically exposes the end of said pipe when exhaust gases are discharged therethrough.

More specically, the present invention is directed to improvements in closure devices of the general type disclosed in our issued United States Letters Patent No. 2,421,838, dated June 10, 1947, wherein said device includes a frame member in the form of a ring, provided with a laterally extending lug to which a counter-weighted closure flap is pivotally connected.

Desirably, such devices should be constructed and arranged so that the closure liap is free to move about its pivotal connection in response to the presence or absence of pressure of the exhaust gases in the exhaust pipe. It is recognized that devices of this general type, by reason of their position of use, are subject to relatively high temperatures by reason of the exhaust gases passing through the exhaust pipe, and hence the metal parts of the closure device are subject to substantial expansion and contraction over a period of time. By reason of such a condition, it sometimes happens that the pivotal connection of the closure flap becomes impaired to the extent that the closure flap does not readily move in response to the presence or absence of pressure of exhaust gases and thus fails to perform its intended function.

'Ihe main object of the present invention is to provide a novel form of pivotal connection or mounting for the closure flap which will insure satisfactory operation of the closure ap for long periods of time.

Another object is to provide an improved pivotal mounting for a closure device of the character indicated which will reduce wear and friction of the moving parts to a practical minimum.

A further object is to provide a novel pivotal mounting for a closure device of the character indicated which insures adequate lubricant present at the bearing surfaces of the pivotal mounting over long periods of time.

Other objects and advantages of this invention will be apparent from the following description, taken in connection with the accompanying drawing in which:

Figure 1 is a plan View of a closure device provided with the novel pivotal mounting embodying the present invention;

Figure 2 is a vertical sectional view through the device, shown mounted on the upper portion of an exhaust pipe, taken substantially as indicated at line 2-2 on Fig. 1; and

Figure 3 is a transverse vertical section through the pivot axis of the device, taken substantially as indicated at line 3-3 on Figure 2.

The closure device comprises a frame IIJ, in the form of a split ring, adapted to surround the upper end of an exhaust pipe as indicated at II, as clearly seen in Figure 2 of the drawing. The split ring includes a pair of laterally projecting, transversely spaced apart ears I2 adapted to be connected together by a bolt I4, the bolt-serving to draw the ears together for firmly clamping the ring around the exhaust pipe.

Extending laterally from the frame or ring IIJ, at substantially diametrically opposite relation to the ears I2, is a lug I5, to which aV closure flap I6 is pivotally connected. The closure flap is generally of, circular contour, and provided with a marginal depending fiange I'I, adapted to surround the upper portion of the exhaust pipe II, and seats upon theupper end of the split ring I0. As may be seen in the drawing, the split ring is mounted on the exhaust pipe so that the upper end of the pipe projects slightly above the upper surface of the ring and in such relation that the closure ap will at no time engage the upper end of said pipe.

Formed integrally with the closure flap is a rearwardly extending tail portion 20, constituting a counter-weight, the undersuriace lof which is recessed, as indicated at 2|, for accommodating therein the mounting lug I5 of the split ring, as clearly seen in Figure 2 of the drawing. The side walls 22 of said tail portion, constituting the walls of said cavity 2I, are spaced apart a proper distance so as to provide adequate clearance for the lug I5, as may be seen in Figure 3 of the drawing.

The pivotal connection constituting the present invention includes a split type tubular bushing 24, mounted by a press-lit in an aperture 25, extending transversely of said lug I5. Said bushing is preferably hardened so as to insure minimum friction and reduced wear. Threaded into the side walls 22 of the tail portion, forming the sides of the cavity 2 I, are headless screws 28, the inner ends of which include extensions in the form of cylindrical trunnions 3A0, adapted to be projected into the ends of the bushing 24 as seen in Figure 3 of the drawing. The trunnions are dimensioned with respect to the internal diameter of said bushings 24 so as to insure a relatively snug t while at the same time providing adequate clearance to insure free movement of said trunnions within the bushing. The trunnions are so dimensioned as to provide a space or charnber as indicated at 32, between the ends thereof, as seen in Figure 3 o'f the drawing, for the reception of a supply of high temperature lubricant, so as to insure adequate lubrication between the t-runnions and the bearing sleeve over long periods of use.

The screws 28, when adjusted so that their trunnions project a proper distance into the bearing sleeve, are adapted to be rmly secured in such position of adjustment by means of lock nut 34, and which provide ready adjustment for said screws to insure proper working relation of the parts, such as may be necessary due to wear caused by vibration of the engine.

It will now be apparent that by virtue of the construction herein disclosed, the counter-weight of the tail portion of the flap serves to counterbalance a substantial portion 9i the overhanging weight of the flap so that said flap is free to move about its pivot axis of the trunnions 39, within the tubular bearing 24, in response to the presence or absence of pressure of the exhaust gas within the exhaust pipe H. When the exhaust gas is passing through the pipe, the closure nap is caused to assume a position substantially as indicated in dot and dash outline in Figure 2 of the drawing, and said iiap being stopped at such position by the lower edges of said walls 22 of the tail piece abutting against the ring I0. It will be apparent that when the pressure of the exhaust gas is discontinued, the overhanging weight of the closure iiap will cause said iiap to automatically return to closed position:

The pivotal co'nstru-ction` constituting the present invention thus insures free operation of the closure ap with minimum frictional resistance, and with minimum wear 4on the bearing parts and permits quick and easy 'adjustment to take up any excess side play of the parts;

Although we have herein 'shown and described a preferred embodiment 'of Vour invention, manifestly it is capable of modification and rearrangement of parts without departing from the spirit and scope thereof; We do not, therefore, wish to be understoodas limiting this invention to the precise form lie'rein disclosed, except as We may be so limited by the appended claims.

We claim as our invention:

l. In a closure device of the Vcharacter described, comprising a frame element adapted to surround the terminal portion of an exhaust pipe, a lug carried by and extending laterally from said frame element, and a closure flap pivotally connected to said lug and adapted to normally cover the open end of the exhaust pipe and movable to an open position by the pressure of the exhaust gases discharging through said pipe, said flap having a laterally extending counterweight for counter-balancing a portion of the overhanging weight of said flap, said counter-weight having a cavity formed in its underside between a pair ci laterally spaced apart walls, said ilap being mounted on the frame with said lug projecting into said cavity, between said walls; the improvement wherein said pivotal connection comprises a pair of elements threaded into said walls, defining a part of the cavity, and the inner ends of said threaded elements being formed as cylindrical trunnions projecting into a cylindrical opening formed in and extending entirely through said lug', said threaded elements each being provided with a transverse shoulder at the inner end of the trunnion, disposed in close, spaced relation to said lug for limiting transverse movement of the ilap relatively to the lug, said trunnions terminating in spaced apart relation to form a chamber therebetween for the reception of lubricant.

,2. ln a closure device of the character described, comprising a frame element adapted to surround the terminal portion of an exhaust pipe, a lug carried by and extending laterally from said frame element. and `a closure flap pivotally connected to said lug and adapted to normally cover the open end of the exhaust pipe and movable to' an open position by the pressure of the exhaust gases discharging through said pipe, said ap having a laterally extending counterweight for counterebalancing a portion of the overhanging Weight of said ap', said 'counter-weight having a cavity formed in its underside between a pair of laterally spaced apart walls, said flap being mounted on the frame with said lug projecting into said cavity, between said walls; the improvee ment wherein said pivotal connection comprises a hardened cylindrical bushing fitted into and extending substantially the length of an aperture formed in and extending entirely through said lug, and a pair of screws threaded into said walls, defining a part of the cavity, and having their terminal portions formed as cylindrical trunnions projecting into the Yend portions of said bushing,

said threaded elements each being provided 'with a transverse'shoulde'r at the inner end of the trunnion, disposed in close, spaced relation to said lugV for limiting transverse movement of the flap relatively to the lug, ysaid trunnions being dmensioed lso 'thatl their 'ends terminate inspaced apart relation to form a chamber in said bushing for the storage of a supply of -lubi'icai'it therein. ,Y Y. n

'cinifisi'fiY HARRY DGRATHEA L. FORT.

REFERENCES CITED The Lfollcii/vlg refrencs 'are of iC-d the le of this, patent:

UNITED STATES PATENTS 

